Combustion device



G. VAN DAAM ooMBUsTIoN DEVICE Aug. 20, 1929.

Filed Nov. 18, 1927 "bil WITNESS 1ra/Enron, georeYonBamn, 8

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Patented Aug. 20, 1929.

UNITED STATES GEORGE VAN DAAM, OF PATERSON, NEW JERSEY.

COMBUSTION DEVICE.

Application filed November 18, 1927.

rlhis invention relates to devices for delivering preheated air to the combustion chambers of furnaces over the fuel bed whereby to economize the fuel by effecting combustion of these gases which would otherwise escape, unburned, to the chimney. The principal object of the invention is to secure a good pre-heating of the admitted air and at the same time to construct the device so that it is capable of being formed in parts separately cast or otherwise shaped and thereupon easily assembled with each other. Other objects will appear hereinafter.

In the drawing,

Fig. 1 is a vertical sectional view, on the line 1-1 of Fig. 2, of the improved device Vattached to a portion of an exterior wall of a furnace combustion chamber, or more specifically to the door for the fuel supply opening to such chamber;

Fig. 2 is a front elevation of said door, partly broken away and showing the device in section; and

Fig. 3 is a side elevation of a furnace embodying my invention and illustrating automatic control of my device.

Let l represent the wall of a furnace and 2 a part thereof which is hinged or otherwise movable so as to leave an opening in the wall, as the opening 3 through which fuel is supplied to the combustion chamber 3a (Fig. 3) of the furnace. Following the usual practice I preferably attach my pre-heating device to the door 2, but of course it may be attached to any other portion of an exterior wall 1 of the furnace in which is provided an air inlet, as the circular series of such inlets shown here in the door at 4.

My device is preferably formed Wholly of metal, as by being cast, so as to be a good conductor of heat. It is constructed in three main parts as follows:

5 is the outer member which is conical and generally cup-shaped, here having the shape of a hollow truncated cone and formed with a basal exterior flange or wall 6, and it has a conical re-entrant stem 7 extending from the closed end of the cup-shaped shell of the member 5 toward but short of its other end, the stem preferably gradually flaring toward said base of the member; the stem is internally cylindrical and threaded at its outer end, i. e., where it joins said shell at the truncated end of the member 5.

A second member 8 is formed as a conical Serial No. 234,122.

A third member is formed by a tubular part 12 which at one end may be closed by a cap 13 and at the other end has an integral enlargement or head 14 and near the head is exteriorly threaded as at 15, the said head and what may be termed the shank of said part 12 (except as to its threaded portion) being provided with numerous perforations 16.

These three members are assembled by screwing the threaded shank of the part 12 into the internally cylindrical and threaded bore formed in the outer end of ,the4 stemi' and introducing the shell of member 8 into member 5 so that said shell stands in concentric relation to the shell and stem of member 5, and also that the flange 6 of member 5 squarely abuts the flange 10 of member 8. And, suitable holes 17 being provided in the door and the flanges 6 and 10, the device may be assembled with and secured to the door by bolting thereto, as at 18, or otherwise.

For insuring good heating of the a1r the inner surface of the shell of member 5 may be formed with projections, as 5a.

It will be seen that the device affords a passage means to conduct a stream of air entering at 4-11 first in one direction and then in the opposite direction lengthwise of a given line (which lie in the present case is the axis of the concentric shells, the stem and tubular part) and that that portion of said means through which the air stream travels in one direction is formed to surround that portion of said means through which such air stream travels in the opposite direction, as the passage portion A with respect to the passage portion B, or the passage portion B with respect to the passage portion C. Further that, since in the present instance there is an odd number of such passage portions to be traversed by the air so that it enters the iirst of them at one end and is discharged from the last of them at the relatively opposite end, with respect to the device as a Whole the air is received at one side or end thereof and discharged at the opposite side or end. The air in passing through the device, on account of the tortuous form of the passage means, becomes well heated, and this efl'ect will be augmented by the presence of projections such as 5a. By constructing my device as described so as to attain the tortuous passage I make it easy to form it in several parts and to assemble them. The tubular foraminous headed part 12-14 is not indispensable, but since it is best-that the heated air be diffused on entering the combustion chamber it serves to cause such diffusion and also, on account of the added extent of heating surface which its long inner end portion affords, to

augment the heating of the air.

The door may have a rotary apertured damper 19 normally turned to close aireadmission at 4-11 by a weight 20, and this damper may be connected by a chain or .An air pre-heating device for combustion appara-tus including an outer hollow externally-and internally conical shell open at its larger and closed at its smaller end and having an inner hollow externally and internally conical stem projecting from its smaller toward its larger end, an inner hollow externally and internally conical shell projecting into the outer shell from its larger' toward its smaller end and being spaced from and substantially parallel with the circumferential wall of said outer shell and also the stem, said first-named shell having within its stem at joining said smaller end a cylindrical bore, the spaces between the stem and inner shell ,and the inner and outer shells communicating with each other at the larger end of the outer shell and the space between the inner shell and stem and the space of the stem communieating with each other at the larger end of the outer shell, said device having means to admit air t-o the space between said outer shell and stem at said larger end of the outer shell, and a tubular air-outlet member screwed in the cylindrical bore of the stem and projecting into the latter in spaced relation to its interior conical surface and having in its projecting portion air-escape means.

In testimony whereof I affix my signature.

GEORGE VAN DAAM. 

